1. Field of the Invention
The present invention is in the field of internal combustion engines and specifically relates to a system for monitoring the amount of a liquid chemical additive that is added to the fuel on which the engine runs.
2. The Prior Art
In the present invention, the amount of additive to be mixed with the fuel prior to combustion in an engine is measured and controlled. The additive flow rates, in some instances, are extremely low, and the user wishes to be assured that the proper number of ounces of additive are with a certain number of gallons of fuel.
Several workers in the field have proposed systems for accomplishing this end, and some of the more pertinent systems will be discussed below. From that discussion it will become apparent that none of the systems disclosed in the known prior art permits the user to know whether the system is actually functioning.
For example, in U.S. Pat. No. 4,346,689 Neely discloses an electric pump operated from the dash board of a vehicle, and which pumps additive into the fuel line at a point between the fuel pump and the carburetor. Neely provides a bypass injection line which permits the fuel filters to be bypassed so that the treated fuel can pass directly into the carburetor.
In U.S. Pat. No. 4,161,160 issued to Hicks, et al. on July 17, 1979, there is disclosed a system for adding additive to the fuel line between the fuel supply and the fuel pump. Because the additive is expensive, a selectively operated valve is provided to limit the flow of additive to the time required for the engine to warm up. A small orifice is installed in the additive supply line to limit the flow of additive into the fuel line.
In U.S. Pat. No. 3,148,670 issued Sept. 15, 1964 to Fiedler, et al. there is disclosed a system in which additive is forced under pressure to flow into the fuel line through a tee.
In U.S. Pat. No. 4,253,436 issued Mar. 3, 1981 to Dudrey, there is shown a liquid fuel and additive mixing apparatus that uses a timer calibrated in gallons to operate a constant pressure pump. An orifice limits the flow rate of the additive.
One problem common to all of these prior art systems is that there is no way of determining whether the system is functioning properly or of being assured that the additive is actually reaching its destination in the desired quantity. As will be seen below, the system of the present invention overcomes this basic problem of the prior art systems.